(1) Field of the Invention
This invention relates to an information storage apparatus for use in combination with an information processing device, for example, a personal computer or the like, and, more particularly, to an information storage apparatus using a conventional magnetic disk unit having a flexible magnetic disk.
(2) Description of the Prior Art
The conventional magnetic disk unit comprises a container and a flexible magnetic disk contained in the container. Such containers are generally classified into two types. A container of the first type is made of a thin and soft plastic material and is therefore called a soft jacket in the art. A container of a second type is made of a thick and hard plastic material. The container of the second type is therefore called either a hard jacket or a cartridge in the art. Each of the containers of the first and the second types has an opening for permitting a recording and/or reproducing head to access the flexible magnetic disk.
The flexible magnetic disk is for magnetically recording filing information, such as computer program and/or data to be processed by the information processing device. The flexible magnetic disk is well known in the art as a floppy disk.
In order to record and/or reproduce the filing information on the flexible magnetic disk, a magnetic disk recording and/or reproducing device is used which has the above-mentioned magnetic recording and/or reproducing head. When the magnetic disk unit is loaded into the magnetic disk recording and/or reproducing device, the filing information can be recorded and/or reproduced by the head accessing the flexible magnetic disk. Thus, the magnetic disk recording and/or reproducing device drives the magnetic disk unit to carry out operation of one of magnetic recording and magnetic reproducing of the filing information on the flexible magnetic disk of the magnetic disk unit loaded thereto. From this standpoint, the magnetic disk recording and/or reproducing device is also called a disk driving device.
The flexible magnetic disk of the magnetic disk unit has a predetermined recording capacity. When the filing information has the amount exceeding the predetermined recording capacity, the magnetic disk unit must be exchanged for another magnetic disk unit by an operator of the magnetic disk recording and/or reproducing device.
For a large capacity information storage apparatus, a hard disk storage apparatus is known in the art which comprises an accessing head and a plurality of hard magnetic disks.
The hard disk storage apparatus is, however, expensive because the hard magnetic disk has a cost higher than that of the flexible magnetic disk. In addition, the hard disk storage apparatus is generally incapable of exchanging the hard magnetic disk for another hard magnetic disk. It is therefore necessary to prepare a streamer tape for the purpose of backup for protection of memorized information of the hard magnetic disks.